--  @testpoint:opengauss关键字by(非保留)，作为函数名
--关键字不带引号-成功
drop function if exists by;
create function by(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function by;

--关键字带双引号-成功
drop function if exists "by";
create function "by"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function "by";

--关键字带单引号-合理报错
drop function if exists 'by';
create function 'by'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/

--关键字带反引号-合理报错
drop function if exists `by`;
create function `by`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/